Mechanical time fuse



May 13, 1947. J; E. MIDDLEMISS 2 MECHANICAL TIME F SE Filed Dec. 15,1959 Fig 1- Fig.5.

uuuuuu [4 lnvET-Lt c11 JusaphJi- Mini [119.1111 55 Patenteol May 13,1947 NED ST ll EEKZHANICAL TIME FUSE Joseph E. Middlemiss, Philadelphia,Pa, assignor to United States of America, as represented by theSecretary of War amended April 30, 1928; 370 O. G. 757) The inventiondescribed herein may be manufactured and used by or for the Governmentfor governmental purposes, without the payment to me of any royaltythereon.

ally employed in such trains as is well understood in the art.

As shown in Figs. 1 and 2 the supporting membar it is formed with twosimilar parallel chordal This invention relates to a centriiugally op- 5grooves l2 having rectangular side and bottom erated rack device fordriving a pinion suitably defining walls. The grooves i2 are disposedequiconnected in driving relation with the clockdistant on either sideof the axis of spindle l I work train or" a mechanical time fuse forprojecand the portion (3 of plate It lying between the tiles. grooves I2is formed with the guideways i l for The rack device of this inventioncomprises a apurpose made clear hereinafter. pair of opposed radialmovable racks which Spindle ll is either milled to provide an infunctionin the same general manner as the racks tegral pinion E5 or a separatepinion is suitably in U. S. Patent No. 1,970,207 and British Patentsecured to the spindle as may be desired and two No. 265,583. oppositelyacting similar rack members It are It is an object of the invention toso arrange disposed with one in either groove I2 to act upon the rackdevice as to facilitate the testing of the the pinion l5 and arbor llfor driving the confuse. nested clockwork train not shown.

It is a further object or the invention to so Each rack member itcomprises a rack ll of arrange the rack device that it may be used folrectangular cross-section and of substantially the testing the fusethereafter be reengaged with depth of the guideways it fitted in thegrooves its cooperating pinion to re-run the clockwork l2 and engagingthe pinion It in driving relation. train without necessity of revers ngthe clockwork The racks ll each have weights l8 suitably atmechanism,whereby the time consumed in testtached thereto so proportioned that thecenter ing will be materially reduced and the accuracy of gravityrof therack member it will fall within of adjustment materially increased dueto the the weight l8 as secured to the rack ll. In acelimination ofblllrlng the escapement gear teeth Cordance With t e invention e W ts153 are of the clockwork which invariably accompanies so shapedexternally as to fit the grooves l2 in running the clockwork train inreverse direction. sliding relation and serve to guide the movement Thespecific nature of the invention as well of the racks in cooperationwith the guideways It. as other objects and advantages thereof will so nper ti n the racks is are inserted in the clearly appear from adescription of a preferred gTOOVBS l3 With the a teeth a j t eembodiment as shown in the accompanying drawei hts engaging the pini l5a t e ts ings in whi h; 18 disposed on a circle concentric with the axisFig. 1 is a plan view of a fragmentary portion of pinion It. When aprojectile armed with a of a fuse with the present invention embodiedfuse embodying the racks it is fired the rotation showing the racks nearthe outer extremity of Of the projectile will cause the centrifugalforce their outward movement; developed to act upon the Weighted racksand Fig. 2 is a sectional view taken on the line 2-2 m e them outwardlyn the grooves 1 Outof Fig, 1; ward movement of the opposed racks willexert Fig. 3 is a bottom plan View of one of the racks is a dr v t rquon t s e l I t h pini n of this invention; and I5 and drive theclockwork train connected with 4 is a view in side elevation of the rackthe Spindle ii. y this a e t t e in t al Shown in Fig 3; starting torqueis high as compared with the Referring now to the draviin s bycharacters Sector racks used in l l heretofqle as of reference and moreparticularly to Fig. 1 there the tolfque increases Wlth mcreas? 1nInstance is shown a supporting member it which is genof Welghts from the3X15 of splndle H the orally a circular plate disk member. Severalincreased torque with outward displacement of disks such as member isare superimposed upon the racks will compensate for the retardatlon ofother to form a support for the complete the projectile in rotation asit passes through its clockwork train but as they form no part of the tj y present invention they are omitted from the In t stns t f foraccuracy at the drawings for the e of clarity. clusion of manufacturethe fuse is pun about its ihe merr M: is axially bored to provide a axisby means of a machine for such p pose and hearing for the spin lie orarbor El of a clockthe weighted racks are forced outward by cenworktrain governed by the escapement genertrifugal force to drive theclockwork train. During this test operation the fuse escapement may beadjusted if necessary and at the conclusion of the operation theweighted racks are simply withdrawn from the grooves l2 and reinsertedwith the teeth thereof adjacent the weighted en'ds engaging the pinionl5 as above described. In this manner the necessity of running theclockwork train in reverse to reposition the racks for subsequentactuation by centrifugal force is obviated which saves the time ofrunning clockwork train in reverse and the Wear and burring of the teethof the delicate escapement device. Hence a substantial saving of time isefiected in testing each fuse which is a critical item in quantityproduction and the accuracy of adjustment after being made will not bedisturbed by the introduction of factors not compensated for, such as aWorn or burred escapement, resulting from the reverse driving of theclockwise train after adjustment is made.

Having now particularly described what is at present a preferredembodiment of the invention I claim and desire to secure by U. S.Letters Patent:

In a fuse in combination, a cylindrical supporting member formed withtwo parallel chordal grooves having rectangular side and bottom definingWalls, said grooves being disposed one on either side of the axis of themember equi-distantly and being formed to provide guideways in the upperportions of their adjacent defining walls, a spindle mounted axially ofthe supporting member adapted to drive a clock- Work train, a pinionsecured to the spindle, a rack of generally rectangular cross-sectionhaving teeth adapted to engage the pinion in driving relation mounted ineach of said grooves with its teeth disposed in the guideway thereof,said racks being slidable throughout the length of the grooves andprovided at their outer end portions with depending weights engaging thegrooves in guiding relation.

JOSEPH E. MIDDLEMISS.

REFERENCES crisis!) The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number 7 Name Date 1,970,207 Varand Aug. 14, 1934FOREIGN PATENTS Number Country Date 265,588 Great Britain May 2, 1928

